In the cattle business and in particular, the feedlot industry, forty to fifty thousand head of cattle are located at any given time in a typical feedlot, with an average pen space of 150-250 square feet per animal. When animals are maintained in such close quarters, it is necessary to diligently monitor the health of the animals so that as soon as any particular animal indicates symptoms of sickness, that animal can be removed and treated. Presently, most feedlots utilize a "pen rider" who rides on a horse into the individual pens and looks for animals that appear lethargic or demonstrate some other indication of sickness or poor health. As can be expected, this system is only as good as the particular person's ability to observe such characteristics. Also, these characteristics may only become visible after the sickness has substantially progressed. It would be a tremendous benefit to the animal owner to be able to timely monitor certain physiological parameters of each animal and be able to use these parameters to identify an animal in the early stages of sickness. These physiological parameters typically would include the temperature and pulse rate of the animal. Additionally, the frequency of feed and water intake of an animal are other good indicators of the animal's well-being.
Various patents have attempted to allow the user to monitor a farm animal's temperature in order to allow early detection of fever or illness. Most of these devices are designed to be implanted into the animal or inserted into a bodily canal. These devices are hard to use because they are either difficult to insert or are easily dislodged or expelled by the animal. Furthermore, implanting the devices via an incision itself creates a risk of infection and illness.
U.S. Pat. No. 4,865,044 provides a device that is implanted in the cow's ear or attached to the ear canal of the animal. The device includes a thermistor to detect the internal temperature of the cow, and also provides means for compensating for ambient temperature when the device has fallen out of the animal's ear or ear canal.
Similarly, U.S. Pat. No. 4,854,328 discloses a capsule, containing a temperature sensor and a transmitter, that is implanted into an animal, such as at the base of the skull. A receiver is placed on a tag that is attached to the animal's ear, much like an earring. The ear tag has an indicator that provides a warning when the animal's temperature is out of a predetermined range.
U.S. Pat. No. 4,399,821 discloses implantable devices that would allow for monitoring one or more physiological parameters of free moving animals.
U.S. Pat. No. 3,893,111 also discloses a capsule that is embedded into an animal to allow for remote monitoring of the animal's temperature.
U.S. Pat. No. 3,781,837 provides a device that consists of an electronic package that is fastened around the animal's neck and that is also connected to a thermistor sensing element which is implanted in one of the ear canals of the animal. When the temperature sensor indicates that the animal's inner temperature is out of a predetermined range, an audio, visual, or radio frequency alarm is provided to indicate that the animal should receive treatment.
Other patents have focused on monitoring and measuring the feed consumption and weight change of animals. In U.S. Pat. No. 3,465,724, an animal wears a device that is sensed by the feeder and opens the feed bin if it is the right animal. The system monitors the feeding times and amounts consumed by the animal.
U.S. Pat. No. 3,541,995 discloses a feed monitoring system that includes an interrogator and a transponder that allows for recognition of individual animals. The transponder measures the dwell time of the animal at the feed station and dispenses a preprogrammed feed amount for that animal to control its feed intake. Only when another animal enters the feed zone will additional feed be discharged at that station.
U.S. Pat. No. 3,929,277 discloses another animal feed monitoring system that senses an identification tag, attached to the animal's ear or embedded under its skin, and weighs the amount of feed consumed by the animal. The information gathered on each animal is stored within a memory bank for later use.
U.S. Pat. No. 4,532,892 discloses an animal feeding and monitoring system that includes an electronic tag attached around a cow's neck for identifying specific animals and then controlling the amount of feed that is dispensed to that particular animal.
U.S. Pat. No. 4,617,876 discloses a monitoring system comprising an ear tag and a scale in a feed and/or water stall. Only one cow at a time can enter the stall, and is automatically weighed as it is drinking or eating in the stall.
However, none of these systems provides for a monitoring system that is simple to use, that is nonintrusive to the animal, that has the flexibility of providing different types of information depending on the user's particular need.